Improvement in steam-engines



4Shevekts--Sheet1.` Reciprocating Engines.

D. A. GREENE.. No. 122,248..

Patented Dec. 26, i871.

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l 4 She`ets``f$heet 2. Reciprocating Engines.

Patnted Dec. 26, i871 D. A'. GREENE.. No. 122,248..

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9732 352mm m D. A GRAEEN'. Reciprocating Engines.

No. 122,248. y Paienied Dec.26,1a71.

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Sheets--Sheet 4. Reciprocating Engines.l

Patented Dec.26,187i.

D. A.. GREENE. No. 122,248.

UNI'rnn STATES DARWIN A. GREENE,

or NEW YORK, N. Y.

IMPROVEMENT IN STEAM-ENGINES.

Speciiication forming part of Letters Patent No. 122,248, dated December26, 1571.

To all whom it may concern:

Be it known that I, DARWIN A. GREENmof New York city, in the State ofNew York, have invented certain new and useful Improvements inSteam-Engines.

The invention relates to the general construction and arrangement of theparts by which the engineis made compact, easily accessible, moreportable, and very nicely balanced; to peculiar means for operating thefeed-pump, which alford marked advantages; and to peculiarities in themeans for connecting and disconnecting the valve motion in starting andstopping.

The following is a description of what I consider the best means ofcarrying out the invention. The accompanying drawing forms a part ofthis specification.

Figure 1 is a front elevation, and Fig. 2 is a side elevation of theengine entire. Fig. 3 is a vertical section through my bed-plate on theline S S in Fig. 4. Fig. 4 is a plan view of the bedplate. Fig. 5 is asection of the bed-plateon the line T T .in Fig. 4. Figs. 6 and 7 aresections through the cylinder and adjacent parts on a larger scale. Fig.6 is a central vertical section.

. Fig. 7 is'a horizontal section on the line S S in Fig. 6. Figs. 8 and9 represent the pump mechanism in section and elevation. Fig. 8 is avertical section on the plane of the axis of the pump. Fig. 9 is anelevation of the same parts. The remaining figures show detailsdetached. Fig. 10 shows the hooking and unhooking gear in eleva- Fig. 11shows the same in plan. Fig. 12 shows the beam in elevation, and Fig. 13shows the same in plan.

Similar letters of reference indicate corresponding4 parts in all thefigures.

A is the xed frame-work, considered collect ively, the several partsbeing indicated by A1A2,

&c., when necessary. B is the cylinder, mounted in an. elevatedposition, as represented. The piston-rodc extends downward therefrom,and connects with the cross-head C', running on slides A2, andcommunicating motion, through a short link, D, to a stout lever, E,turning on a center, c, near the base of the frame-work, but sufticiently elevated to allow the beam to rock above the base of the bed-plate.The entire bed is formed in'one casting, A1, with a rim or raised ridgearound its edge, as indicated by a. AThis con-- struction of the bedcauses it to hold all the drippings of water, oil, or anything else, andretain them in a stratum over the bed, and allow them to be drainedeither constantly or at intervals through the drain-pipe a. This may beprovided with a cock or other means of control, not represented. Aconnecting-rod, F, communicates motion from the beam E to the crank G1on the main shaft G, which latter carries any-wheel, G'Sadapted to servealso as a pulley to communicate motion to the mill-work or-other work tobe driven through the medium of a belt, not represented.

-The valve-chest is on the front of the cylinder,

and receives steam through a connection, H, from a pipe and boiler, notrepresented. The steamV is admitted to the cylinder by a slide-valve, I,which is reciprocated through the medium of a valve-rod, i, whichcommunicates motion from a bent rock-shaft, J, in front of the beam atthe bottom, and which is bent, as represented, to allow the keys andother work on the front of the cross-head and link D to project aconsiderable distance, if necessary. tThe rock-shaftJ is operatedthrough the medium of its armsJ and an eccentric rod, K, leading from aneccentric, K, all in the usual manner, except in the provision Aforengaging and disengaging the parts. A hook is formed on theeccentric-rod adapted to engage with the pin on the rock-shaft arm. Thehooked end of the eccentric rod is raised and lowered by means of alight link, k, which connectsa pin on the eccentric rod K to a piu on arevolving part, L, which is free to be revolved at will by turningloosely on the end of the rock-shaft J, being controlled by the shorthand-lever L. To unhook or disengage' the eccentric rod from the pin onthe rock-shaft the engineer pulls the handlever L', and turns it intothe position opposite of that shown `in Fig. l0, and the engine isstopped. To hook on or make the connection the engineer turns the handleL by pushing it around so as to cause it to perform a half revolution.This lowers the link 7c and allows the hook on the eccentric rod K to engage with the pin on the rock-shaft. Thus conditioned the eccentricmaintains the proper rocking motion of the rock-shaft, and consequentlyimparts the proper motion to the slide-valve I. The arrangement of theparts requires a slight play on the link kat eachrocking motion. This`is allowed for making a short slot in the link k.

This slot may be either on the pin which connects this link to therevolving part L or on the other on the upper side, as indicated by il.One of its extreme highest position. It follows that it pin whichconnects it to the eccentric-rod K. It is sufficient in practice toallow a quarter of an inch or less for alarge engine. Without such jprovision a slight lift would be given to the eccentric hook-at eachrevolution, and this, although slight, wou] d induce a iapid destructivewear and abrasion ofthe surfaces in contact. The device thus provided isvery convenient and durable.

The slide-valve is liable to descend by gravity into too low a positionwhen unhooked. This, if permitted, would induce various evilsnot theIleast of which might be the moving ofthe rocker-arm J' into such aposition that the hook on the eccentric-rod K could not engage with it.To prevent this an adjustable stop is provided inthe valve-chest by thescrew d2, which is capable of being adjusted with very great delicacy.After setting the valve properly this screw is turned into such aposition that at each descent of the valve the screw comes very nearlyor quite in contact with the interior of the valve-chest at the bottom.It may be guarded against any possible derangement of position afterwardby a jamnut, if Vsuch should be necessary. Y To avoid a liability tolift the valve too high when starting the engine by hand a similar screwis also provided these stops prevents the valve from being ever movedbeyond its extreme lowest position, and the other prevents iti'rom beingever moved above cannotbeplaced by any unskillfulness or thoughtlessnessin any position where the hook on me eccentric-rod is .not ready toengage with it when lowered forthe purpose. Y Y

` There is no joint in valve-rod. The motion of this member of themechanism is nearly but not quite vertical. The upper end slidesvertically, while the lower end describes a small arc. It has beencommon in small engines, and even in locomotives having long connectionsbetween the valve and rocker-arm, to make the valvestem'without a joint,and to cause it to spring sufficiently to allow for its slight deviationfrom a constant line. This would involve difficulties on an engine ascompact or with as short connections as this. I avoid them by averysimple device. The valve-stem is made rigid or with a moderatedegree of elasticity, and the Obliquity of its position is allowed forin the gland of the stuffing-box at the base of the steam-chest. Thesurface on the interior at the base of the steamchest is elevated aroundthe valve-rod, and at the extreme upper end of this elevation it fitsquite closely. Below this it is filled with packing, which isintentionally and necessarily a yielding material and will allow verycompletely for its slight deviations of positions to one side and theother. vThe feed-pump Mis of the ordinary solid-plunger variety, and ismounted directly below the overhanging end of the main shaft. The engineis intended to run very rapidly, and it is important to the smooth andsuccessful working ofthe pump that it shall reciprocate at only amoderate speed. I employ a friction-gearing to reduce the motion, andhave adapted it to perform in its ordi- 'u frictional contact. Thepump-pluri germ is worked by means of a connection', m1, whichreceivesmotion from a pin, m2, xed in a radial slot, M2,

vin the wheel M1. This pin m2 may be set out and in, so as to give thepump-plunger the required amount of throw. l

Iconstruct the parts capable of adjustment to pump a much greater amountthan is needed to supply the. boiler, so that the surpluswater may Vbeused to supply an elevated tank, or for other purposes; and it can beadjusted exactly at the center in any case, when necessary, so that thepump will remain absolutely motionless. The

main resistance to the motion of the pumpis during the descent of theplunger m. Itis a peculiarity of my arrangement that it provides for anincrease of friction between the friction-wheels at this period withoutinducing any excess of friction at other times, whatever may be theresistance to the descent of the plunger m; and this will vary accordingto theA pressure of the steam. A corresponding increase of friction isinduced between the large friction-wheel M1 and the smallfriction-wheel. It follows that the contact of these friction-wheels isalways just suf-l The pipe which drains the base of the cylinder ismarked S, and its cock s. The pip'e which drains the bottom of thesteam-chest is marked R, and its cock fr.

I propose, in large'engines, to apply some compact form of water-trap inplace of the controlling means r and s here represented; but for smallengines the screw-valves shown are amply sufficient. 'The'parts beingallproperly proportioned to afford proper strength and stiffness, it isusually or invariably found that the weight of the piston and itsconnections exceeds the weight of the connecting-rod and crank. Icompensate for this difference by giving an excess of weight to the beamat the end which connects to the crank, as shown in detail in Figs. l2and 13.

Some of the advantages due to certain features of the invent-ion may beseparately enumerated, as follows: First, by reason of the arrange--ment of the elevated cylinder and shaft with the single-loaded beambelow, connected as represented, to make an inverted beam-engine, I am'able to mount the shaft at a just suflicient elevation, and to employ alarge iy-wheel Without cutting through the iloor or ceiling. It alsoa-llows the employment of a continuous bed-plate under the entireengine, and the pillow-blocks being mounted on aV rigid frame-work, andconnected together by the bed-plate, holds the work more strongly andreliably in line. The entire framing is a unit, and the engine isremarkably compact and stiff, while every part is easily accessible.Second, by reason of the employment of the friction-gears M1 and pin m2,adjustable in the slot M2 for variably operating the pump plunger, asspeciiied, I am able to vary the quantity pumped Within Wide limits withvery simple and noiseless mechanism. Third, by reason of the mounting ofthe friction-gear Wheel M1, slotted and carrying an adjustable pin, m2,and pump-connections, as represen ted, with the Wheel M1 on a springbearing directly in line between the friction gear-wheel M1 and thepump, I am able to render available the vari able resistance of the pumpto increase the contact of the frictiongears at the right momentwithoutany considerable excess at any time, as herein specified. Fourth, byreason of the construction and ar rangement of the revolving part L withits 11andleL and link L, connecting it to the eccentric rod Kl, I amable to hook and unhook the engine by very simple and efficientmechanism, and to hold the hook efficiently in or out of connectionWithoutinducin g any appreciable friction or Wear.

I claim as myinventionl. The within-described inverted-beam enginehaving the elevated cylinder and shaft, and single loaded beam below,connected and adapted to operate within a rigid castiron 'aming,substantially as herein specified.

2. rIhe rictiongears M1, slot M2, and adjust'- able pin m2, arranged, asrepresented, relatively to the main shaft and to the pump M m., andconnection m1, for thepurposes specified.

3. The arrangement of the friction-gears MI in line with the pump,andthe mounting of the wheel M1 on the spring-bearing', so as to inducea selfacting adjustment of the frictional contact varying with thechange in the resistance of the pump, as specified.

4. The turning piece L L' and link 7c, arranged and operating relativelyto the eccentric hook K and the rcck-shaft arm, as and for the purposesset forth. z

In testimony whereof I have hereunto set my name in presence of twosubscribing witnesses.

DARWIN A. GREENE.

Witnesses:

C. C. LIvINGs,

A. HOERMANN, `(150)

